softfloat: Fix BAD_SHIFT from normalizeFloatx80Subnormal

All other calls to normalize*Subnormal detect zero input before
the call -- this is the only outlier.  This case can happen with
+0.0 + +0.0 = +0.0 or -0.0 + -0.0 = -0.0, so return a zero of
the correct sign.

Reported-by: Coverity (CID 1421991)
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200327232042.10008-1-richard.henderson@linaro.org>
Message-Id: <20200403191150.863-8-alex.bennee@linaro.org>
This commit is contained in:
Richard Henderson 2020-04-03 20:11:45 +01:00 committed by Alex Bennée
parent 076b2fadb5
commit 2f311075b7

View File

@ -5856,6 +5856,9 @@ static floatx80 addFloatx80Sigs(floatx80 a, floatx80 b, flag zSign,
zSig1 = 0; zSig1 = 0;
zSig0 = aSig + bSig; zSig0 = aSig + bSig;
if ( aExp == 0 ) { if ( aExp == 0 ) {
if (zSig0 == 0) {
return packFloatx80(zSign, 0, 0);
}
normalizeFloatx80Subnormal( zSig0, &zExp, &zSig0 ); normalizeFloatx80Subnormal( zSig0, &zExp, &zSig0 );
goto roundAndPack; goto roundAndPack;
} }